1. Field of the Invention
The invention relates to an endoscopic instrument for internally sampling tissue specimens under constant visual inspection, comprising a shaft having a closed distal (i.e. leading) end and having a lateral viewing and cutting aperture near said closed end, which may be coupled to a negative pressure for example via a suction passage and whereof the rim forms a mating cutting edge which cooperates with a cutting edge displaceable within the shaft.
2. Description of the Prior Art
To obtain tissue samples from bodily cavities, which are to be examined, in particular of trophoblast tissue which encloses the "growth" bag of an embryo, it is known to lead a cannula or a biopsy forceps to the tissue which is to be examined to sample a tissue specimen under ultrasonic monitoring or visual observation by means of an optical system. If use is made of ultrasonic monitoring, the disadvantage exists that no direct observation is possible, and if use is made of biopsy forceps under endoscopic observation, the tissue specimens are commonly quantitatively inadequate for examination.
Shafts connectible to a negative pressure and comprising a distal head which is equipped with a lateral aperture the rim of which forms a mating cutting edge for a cutting blade movable within the head, are also known for sampling tissue specimens. These instruments may be led up to the point in question of the tissues but without visual observation, or else under complex X-ray monitoring.